IE904692A1 - Device for continuous casting of molten metal into thin¹strips between two rolls - Google Patents

Abstract

This device comprises two parallel and rotating cylinders (rolls) (3) separated by a casting space, as well as two lateral closure walls (4) applied in a leaktight manner against the ends of the cylinders (rolls) (3) and lined with insulating refractory (5); each lateral wall (5) being of the "negative-insert" type, leaktight refractory seals (6), consisting of consumable flexible strips, are interposed between the front faces (3a) of the cylinders (rolls) and the lateral walls (4), and advance during casting at the same speed as the cylinders (rolls) (3) by virtue of suitable drive means. The seals (6), unwound from feed reels, prevent infiltrations of liquid metal between the front faces of the cylinders (rolls) (3) and the lateral walls (4), and thus any risk of blocking of the device. ……

Description

The present invention relates to a device for the continuous casting of a molten metal into thin strips between two parallel and rotating rolls, comprising lateral walls for closing the casting space, applied in a leaktight manner against the ends of the rolls and lined with an insulating refractory lining.

In these devices, it is essential to prevent, as far as possible, infiltrations of molten metal between the lateral closure walls and the rolls. In fact, any infiltration of molten metal between these components gives rise to wear of the refractory and of the rolls, attachments of the solidified cast metal on these components and, finally, jamming of the machine.

The invention thus aims to propose a solution to this problem.

According to the invention, the casting device comprises, for each lateral wall, refractory leaktight gaskets consisting of flexible bands interposed between, firstly, a front face of a roll and one of the said lateral walls, which presses the gasket against the said front face of the roll, and, secondly, a curved bearing surface of which the axis of curvature is coincident with that of the roll, and the side of the refractory lining of the lateral wall, the section of the gasket being such that the surface thereof, which is located against the side of the refractory lining, is also in the extension of the cylindrical surface of the roll, and means for driving these gaskets in order to cause them to run, during casting, at the same speed as the speed of rota30 tion of the rolls.

The lateral walls used are of the so-called negative insert type, that is to say those in which the refractory surface in contact with the molten metal is axially offset as a recess from the ends of the rolls.

This insert is referred to as negative in order to contrast it with the positive inserts which penetrate inside the inter-roll space and thus delimit a casting space whose length is less than that of the rolls, such as described, for example, in the document FR-A-2,636,259 .

A pair of consumable flexible gaskets is thus disposed on the sides of each negative insert, between the edges of the refractory lining and the ends of the rolls.

More precisely, these gaskets are disposed between, firstly, a front face of a roll and one of the said lateral walls, which presses the gasket against the said front face of the roll, and, secondly, a curved bearing surface of which the axis of curvature is coincident with that of the roll, and the side of the refractory lining of the lateral wall, the section of the gasket being such that the surface thereof, which is located against the side of the refractory lining, is also in the extension of the cylindrical surface of the roll.

Under these conditions, the twisting path which the molten metal must follow in order to possibly infiltrate outside the device is such that any substan20 tial infiltration is rendered virtually impossible.

The curved bearing surfaces for the gaskets may either be fixed, the gasket then sliding over the latter, or movable and driven in rotation with the roll, it then being possible for a groove to be produced on the edge of the rolls, in which groove the gasket is placed.

Other features and advantages of the invention will become apparent during the following description which is given with reference to the appended drawings which illustrate a non-limiting embodiment thereof by way of example.

Figure 1 is a half-section, half-elevation view according to 1-1 in Fig.2 of an embodiment of the device for continuous casting of molten metal according to the invention.

Figure 2 is a view in transverse section according to 2-2 of the device in Fig.l.

The device shown in the drawings is intended for _ the continuous casting of a molten metal 1 into thin strips 2 between two parallel and rotating rolls 3 which are driven in rotation by means which are known per se and are not shown.

At each of its ends, this device comprises a lateral wall 4 for closing the casting space between the rolls 3, lined on the inside with an insulating refractory lining 5. Each lateral wall (also referred to as lateral side dam) is said to be of the negative insert type, that is to say that it is positioned such that an axial clearance is retained between the surface of its refractory lining 5 and the planes of the front faces 3a of the rolls 3.

A pair of leaktight gaskets 6 is associated with each lateral wall 4, the said gaskets consisting of flexible bands interposed, in an axial direction parallel to the axes of the rolls 3, between the front faces 3a and the wall 4. In the transverse direction, perpendicular to the previous direction, each gasket 6 is inserted between the refractory lining 5 and a fixed guide 7 having a circular bearing surface 7a supporting the gasket 6.

Each gasket 6 is unwound from a feed reel 8 placed above the coinresponding roll 3, it being possible for the lower belt of the gasket 6 to be kept stretched by means which are not shown, or rewo- i on a roil, if the entrainment of the gasket by the roils alone proves to be inefficient.

In order to ensure the leaktightness of the casting space and the entrainment of the consumable gaskets 6 at the same speed as that of the rolls 3, the device is supplemented, in the case of each lateral wall 4, by a spring 11 which exerts a thrust parallel to the axes of the rolls 3 on the said wall 4, which compresses the flexible gaskets 6 between the front faces 3a and the surfaces 4a of the walls 4. Therefore, the gaskets 6 grip onto the roughnesses of the faces 3a, which force them to run at the same speed as the rolls 3.

In an alternative embodiment, this entrainment of the gaskets 6 may be ensured by notches or serrations (not shown) made on the front faces 3a and which engage themselves in the flexible material of the gaskets.

In any case, the gaskets are displaced at the same speed as the rolls 3. The notches or serrations may, naturally, be replaced by any equivalent means, such as barbs.

The gaskets 6 may be produced from a suitable fibrous refractory material, for example from a silicone matrix. They may also be made from a refractory fabric, such as alumina fibres or carbon paper. The gaskets 6 make it possible to virtually eliminate any infiltration ◦f molten metal between the roils 3 and the walls 4. Thus any risk of jamming of the device as a result of infiltrations at these locations is virtually prevented.

Claims (6)

1. Device for continous casting of molten metal into thin strips (2) between two parallel and rotating rolls (3) , comprising lateral walls (4) for closing the casting 5 space, applied in a leaktlght manner against the ends (3a) of the rolls (3) and lined on the inside with an Insulating refractory lining (5), characterised in that it comprises, for each lateral wall, leaktight refractory gaskets (6) consisting of flexible bands, interposed 10 between, firstly, a front face (3a) of a roll and one of the said lateral walls (4), which presses the gasket against the said front face of the roll and, secondly, a curved bearing surface (7a) of which the axis of curvature is coincident with that of the roll, and the side of 15 the refractory lining of the lateral wall, the section of the gasket being such that the surface thereof, which is located against the side of the refractory lining, is also in the extension of the cylindrical surface of the roll, and means for entraining these gaskets in order to 20 cause them to run, during casting, at the same speed as the speed of rotation of the rolls.

2. Device according to Claim 1, characterised in that the ends (3a) of the rolls (3) are equipped with circular guides (7) supporting the gaskets (6), the 25 latter being interposed between these guides and the edges of the refractory lining (5) of the lateral walls (4) .

3. Device according to Claim 1 or 2, characterised in that the means for entraining the gaskets (6) comprise 30 serrations or barbs made on the ends (3a) of the rolls (3) and serve as means for catching the bands forming the gaskets (6).

4. Device according to one of Claims 1 to 3, characterised in that the gaskets (6) are unwound from 35 feed reels (8) located above the rolls (3).

5. Device according to one of Claims 1 and 2, characterised in that the means for entraining the gaskets (6) comprise springs (11) exerting thrusts parallel to the axes of the rolls (3) on the lateral walls (4), which compress the gaskets (6) between the said walls and the rough front faces (3a) of the rolls (3).

6. A device for continuously casting of molten metal into thin strips according to any preceding claim substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.